The field of power transformer diagnostics is characterized by inexact reasoning and reasoning under uncertainty. Lack of information on the construction and design of a transformer, limited test opportunities, uncertain operating conditions and a lack of empirical data combine for a task that is far from an exact science. Interpretation of test results is more of an art than a science. Practitioners must examine sparse evidence from a variety of sources and make an educated guess as to the presence of a potential fault condition, the severity of that fault condition and the appropriate corrective action (which often is limited to costly replacement).
Unfortunately, in today's industry environment, these same activities must be performed with reduced manpower, reduced domain expertise and an ever increasing amount of raw data. In addition, asset management and maintenance decision are coming under increased scrutiny, both from within the company as pressures to constrain costs mount, and from external regulators. Transformers are a key component in power delivery. Transformer failures can cost millions of dollars in consequential costs besides leading to other system reliability and operational challenges.
Accordingly, there is a clear need for an established, defensible, transparent and repeatable condition assessment methodology.